Economic Comparison of Herbicides for Johnsongrass (Sorghum halepense) Control in Glyphosate-Tolerant Soybean (Glycine max)

Abstract

Returns to land, management, and risk were compared where glyphosate and four graminicides (quizalofop-P, fluazifop-P, sethoxydim, and clethodim) were used for johnsongrass control in glyphosate-tolerant soybean. In 1994 and 1995, returns to land, management, and risk for glyphosate-tolerant soybean were highest using glyphosate and lowest using sethoxydim. Break-even analysis showed that yields needed for equivalent returns with any nontransgenic soybean cultivar treated with any of the graminicides could range from 67 kg/ha less to 202 kg/ha more than the yields achieved with glyphosate. Based on this methodology, farmers would increase their return to land, management, and risk by planting glyphosate-tolerant soybean if expected yield from a standard cultivar treated with a standard herbicide program were less than the break-even yield.